Where deep bores are drilled to gain access to subsurface formations, for example as in the oil and gas exploration and production industry, it is conventional to line the drilled bores with metallic tubulars. Typically, the tubulars take the form of thick-walled cylindrical tubulars sections which are coupled together and run into the drilled holes as strings. Methods of producing, handling and running in of such tubulars are well established, however problems remain, particularly in running tubular strings into bores, and these problems become more acute as attempts are made to access hydrocarbon deposits in more challenging locations, and the drilled bores become longer and more highly deviated.
It is among the objectives of at least one embodiment of an aspect of the present invention to provide downhole tubulars which obviate or mitigate some of the problems associated with existing tubular forms.